Solutions Trench around castle/building has 7 entries with similar clues
- ditchBoundary trench
- fosseA long ditch or trench
- dugoutSoldiers trench
- paradosFortified wall behind a trench for protection from rear
- traverseDefensive barrier of mud bank in front of a trench
- pioneer-corpsArmy body preparing trenches, etc.
- challenger-deep-in-the-marina-trench-in-the-north-pacific-oceanThe world's deepest ocean trench